Spark-plug.



; rariteiten fffiosnrnt insana, or Trinitron, maw amasar.'

SPARK-PLUG.

Lacasse.

. To all 'whom t may concern:

Be it known that I, JosEPH Meana, a' citizen of the United States, and a resident of Trenton', in the county of Mercer and State of New Jersey, have invented a vnew and Improved Sparl{Plug, of which the following is a full, clear, and exact description.

` shell or body of the spark plug This invention relates to a double gap spark plug and the invention has for its general objects to improve and simplify the construction of devices of this character soA as to be reliable and efficient in use and comparatively inexpensive to manufacture.

A more'speciicobject of .the invention is to provide a spark plug in which the porcelain bushing is so designed that it can be inexpensively made and at the same time `firmly hold one1 ofthe vactive electrodes and the dead or insulated electrode.

With such and other objects in View the inventioncomprises various novel features of construction and arrangement ofVv parts which will be more fully set forth hereinafter taken in connectionv with the accompanying drawings in which similar reference characters are employed to designate corresponding parts and in which- Figure l is a central vertical section of the spark plug; and Fig. 2 is a bottom plan view thereot.` v

Referring to the drawings, l lndicates a be of any improved constructiin and in which is the electrode 2. In the shell is clamped a porcelain or otherbushing 3 which is molded with two parallel passages 4 and 5 for thevelectrodes 6 and 7 respectively which are in the form of wires of suitable not become displaced.

diameter. rllheelectrode 6 is placed centrally between the electrodes 2 and 7 and in suitable proximity thereto to provide the snark gaps 8 and 9. 1n thcuppcr end' oi t e bushing 3 are opposit'ely disposed rccesses or chambers 10 and 11 and into the chamber 10 extends the'upper end of the lelectrode or conductor 6 which upper end is bent backwardly so that the electrode can After the electrode is bent at 12 the chamber 10 is lled with la suitable sealing material 13. In the cham- Specication of Letters Patent.

ber l1 is fitted the eye or aperture head ift vtrode 7. It will be understood that the vother side of the circuit is connected with the engine on which the sparkplug shell l is grounded so that the ignition current Will pass between the electrodes 2 and Thy way of the gaps and the insulated or-dead elec trode 6.

From the foregoing description taken in connection with the accompanying drawings the advantages of the construction and method of operation will be readily apparent to those skilled in the art to which the ine vention appertains, and while i have described the principle of operation of the inn \'enti on,'togetl1er with the device which it no\\'` consider to be the best embodiment thereof, 1 desire to have it understood that the device shown is merely illustrative and that such changes may be made when de sired as are within the scope of the appended claim.

I claim:

A spark plug comprising a shell having Patenten am. so, isis.

Application led August 22, 1917. Serial No. 137,591.

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longer passage, a stud having an apertured head disposed in one ot' the chambers and throughu'hich the second-mentioned elec trode passes, a nut on the stud to torni a binding post, a third electrode in the shorter passage and disposed between the first and second electrodes, the outer end of the third electrode being disposed in the other cham ber and bent back therein to form ari anchorage, and scaling material in the lastn mentioned chamber for rigidly holding the third electrode in place.

JOSEPH MEABA. 

